Evolution in ContextRobyn Williams Speaks with Dr Colin Groves
Ockham's Razor - ABC Radio National Transcripts Sunday, 10 August, 1997
Dr Colin Groves received his PhD in 1966. He held fixed-term appointments in the University of California and in Cambridge University before migrating to Australia to take up a post in the A.N.U., Department of Archaeology & Anthropology (formerly Prehistory & Anthropology) where he is now Reader.
Do you remember that delicious response to the moon landing in 1969 when disbelievers claimed it had all been staged at a TV studio in Burbank? There were a few similar comments about Mars the other week, suggesting that the intrepid little explorer was really sending pictures back from some desert in the mid-west of America. Some people are never convinced.
Well, Colin Groves is himself a skeptic, but of the scientific kind. In today's talk he asks what it really takes for some people finally to accept some of the big ideas of our age, such as the theory of evolution. Dr Groves does archaeological research at the Australian National University in Canberra.
We live on the surface of a solid globe, part of a planetary system in orbit about the Sun, which itself is an insignificant star in the Milky Way galaxy. This much we think we know, or do we?
The best-know objectors to this model are the Flat Earthers. A flourishing and aggressive bunch as recently as the late 19th century, they are today an insignificant rump, a bit clapped out intellectually. The best that one of them could manage, when challenged with a photograph of a very globular Earth taken from space, was 'Yes, it's easy to see how someone might be fooled by that'.
But there is another model too, that puts itself forward as an alternative to the Copernican view. In this view the Earth is spherical all right, but we are on the inside of it. The stars and the planets are tiny bodies, revolving around the earth's internal axis. The sun travels in a spiral, reversing itself every six months. Light (which travels in arcs) gets slower and slower as it approaches the centre of the Earth and finally stops, so that we can never see all the way to the other side. The only way to get to the other side is around the surface. If we tried to cut across the centre we too would go more and more slowly and get smaller and smaller. If we tried to drill our way through the ground to get out of this cramped and claustrophobic system, its peculiar laws ensure that we would come out at the opposite side of the Earth!
The Hollow-Earth model is discussed by Martin Gardner in the Summer 1988 issue of The Skeptical Inquirer and he makes the point that it actually cannot be refuted! Its auxiliaries, the ad-hoc laws of motion and time, the behaviour of light and so on, that are necessary to make it work ensure that it is entirely physically and mathematically consistent. The reason why most of us do not believe in it, but instead embrace the Copernican Theory, is the principle called Ockham's Razor - don't multiply your basic postulates unnecessarily. The Principle of Parsimony, that's the principle on which all science operates, and must operate.
Science is the name we give to the system that describes how we know what we know and simplicity - Ockham's Razor - is the key to this process of knowing. Every branch of science has its great unifying theoretical models: the Theory of Valency, the Theory of Electromagnetism, the Theory of Relativity, the Theory of Quantum Mechanics, the Copernican Theory. What they all have in common is Ockham's Razor: they simplify the basic assumptions. That is why they are such powerful explanatory tools. The biological equivalent is the Theory of Evolution.
What Charles Darwin did was that he proposed a mechanism for evolution - Natural Selection - and amassed a vast, unanswerable corpus of evidence for it. The mechanism was so simple, so elegant, as to make his friend Thomas Huxley exclaim, 'How incredibly stupid of me, not to have thought of that myself!'. The evidence he produced made it quite clear that evolution was biology's Ockham's Razor. It explained the Law of Faunal Succession more parsimoniously than did the Revolutions of the Globe. It explained the facts of embryology, the paradox of homology, the peculiarities of animal distribution, the nestedness of taxonomic categories. Any one of these would be sufficient on its own to convince most people that evolution is more parsimonious than any conceivable alternative.
A scientific hypothesis starts life as a tentative explanation for certain observations. A hypothesis that has survived all the tests we can throw at it is said to be Highly Corroborated or 'Robust', and if it has been shown to have a wide explanatory power as well it achieves the exalted status of a scientific Theory. Don't demean the great Theories of science by calling any fly-by-night hypothesis a 'theory'. A Theory is a model of the way systems work; more than that, it is well corroborated and continues to be tested (the Theory of Evolution gets tested every time anyone puts a spade in the Earth and brings out a fossil); more than that, it is Ockham's Razor at work.
So who doubts evolution? The creationists, that's who. Creationists are the Christian, Jewish and some (but not all) of the Muslim Fundamentalists; and don't forget Hindu Fundamentalists too. Creationists are Pat Buchanan, Jimmy Swaggart, the late Meir Kahane, and (though I may be wrong here) the late Ayatollah Khomeini. Creationists are not the Pope, the Archbishop of Canterbury, the Chief Rabbi or (as far as I know) the Patriarch of Constantinople or the Aga Khan.
On what basis do these creationists doubt evolution? The real reason is that they have a sacred book which says that human beings, animals and plants were created in much the same form as they exist today; but they give any number of spurious reasons connected with science. I find it despicable that people who claim adherence to strict religious tenets such as 'don't bear false witness' can nonetheless misquote science to give a secular gloss to their religious bigotry.
The tenets of the Judaeo-Christian version of creationism are:
All organisms were created in one week, about 6,000 years ago (some allow for up to 10,000 years).
The geological column was mostly (or, in some versions, entirely) laid down in Noah's Flood.
The fossil record consists mostly of the remains of organisms drowned in that Flood.
Hindu fundamentalism differs drastically, especially in its timescale. The Bible, taken literally, allows for a few thousand years since the creation of everything; the Hindu scriptures have billions and billions of years. The Judaeo-Christian version forbids any evolution whatever. The Hindu version doesn't particularly mind if other organisms evolved, it's just people that can't be allowed to. What they have in common is that human beings have been around from the beginning, and even that most scholarly of all creationist books, the Hindu 900-page Forbidden Archaeology, has to pull out all stops to 'prove' that they were. Genuinely intermediate fossils are tossed aside, 19th-century claims of human remains in very early strata are wheeled out again. At least there's no mention of Noah's Flood.
Noah's Flood plays a big big part in Christian creationist Earth history. We have seen that the Theory of Evolution elegantly explains the Law of Faunal Succession. As the Christian creationists don't believe in long geological ages, and especially not in evolution, Noah's Flood must do the job. How does it fare? We find four arguments used, some of them incompatible with each other:
(1) It's only chance that we haven't found all species at all levels. (The Cambrian elephants are there somewhere; a thousand excavations in Cambrian deposits haven't found them yet, but maybe the thousand and oneth will turn them up).
(2) Hydraulic Sorting: the bigger, heavier animals sank to the bottom during the Flood. [The trilobites must have been heavier than the dinosaurs, that's all].
(3) The more intelligent animals saw the floodwaters rising and ran up to higher ground. [This Faunal Succession business works for plants, too. Everybody knows that flowering plants are more intelligent than ferns or conifers].
(4) The rock strata must be in the wrong order. (Steno was wrong; the 99+% of strata which are in the 'evolutionist' sequence must be due to overthrusting or whatever).
How did all the animals get onto Noah's Ark, two by two or (in some cases) by sevens? A lot of species must be taken on board, but it can be managed. Dinosaurs, for example, could be taken on as eggs. There would be some problems, of course, like how to keep the tigers from eating the wombats, and later ensuring that the wombats got safely back to Australia before the tigers caught up with them. Or like the one put to me by Ian Plimer: how to accommodate, on a wooden ark, 20,000 species of termites.
Does this sound a bit familiar? It's the Hollow Earth again, isn't it! It's the same ad hoc method of explanation; bits and pieces cobbled together to make the machine work and if it still doesn't work satisfactorily, more bits and pieces tacked on until it does. The same blithe disregard for Ockham's Razor and for the same reasons, too. The Hollow Earth model was revealed to its originator in 1869 by an angel and its opponents castigated as servants of the Antichrist. A 20th century version added God sitting on his throne in the centre, and its leading exponents, past and present, have viewed it as their solution to the anxiety that the meaningless vastness of the Copernican universe may engender.
What should we do about these creationists? In September 1995 I was asked by the Daily Telegraph Mirror to provide a short piece for its Education Times section on the trend to so-called 'Christian Schools' in Australia, alongside a similar piece by an advocate of these schools. My piece was butchered and watered down quite a bit, as I might have expected. The arguments advanced in favour of fundamentalist Christian schooling stressed defence of traditional Christian values; the same search for meaning and stability in a changing world as we heard from the Hollow-Earthers. This should not be underestimated as a motivating force for religious fundamentalism. Constant change and uncertainty can generate anxiety and this in turn may feed a fervent will to believe in traditional, unchanging concepts. But a 'will to believe', however passionate, must not be allowed to determine what children learn. I mean science of course, including evolution; but I also mean learning about other ways of thinking - the full richness of human life, multiculturalism in its fullest sense. To learn and to understand is to be just that much more in control, just that much less at the mercy of this changing world that fundamentalists fear so much. Peter Crimmins, the apologist for the Australian Association of Christian Schools, wrote:
an important part of a truly Christian education is the ability to examine what lies behind one's own beliefs and the views expressed by others and to measure these by the truth revealed in the Bible.
Fundamentalists have already hijacked the dictionary: they have changed the meanings of words like Evolutionist and Creation and they seem bent on changing the meaning of Christian. Reading that they now want to change the meaning of whole phrases like 'the ability to examine what lies behind one's own beliefs' is depressing beyond belief.
The whole of science, in all its richness and excitement, must be made available to children in the classroom. Anything less is unfair to them and to society. Science is hypothesis testing. Children must not be given the idea that it is a method of shoring up ones previous beliefs, of confirming ones biases.
More than that, hypothesis testing means humility, the willingness to admit that one may be wrong. Fundamentalist religion teaches the very opposite, the terrible certainty that one point of view is right. To teach that to children - that is not education.